The present invention relates generally to a cooling device for an electric device and more specifically to a cooling device having a filter.
An electric device has a cooling device for cooling the electric device by allowing heat generated by a heat generator such as a semiconductor device mounted to the electric device to be radiated. The cooling device includes a cooler that has formed therein a passage by installation of fins in a sealed housing thereof. The cooler is operable to exchange heat generated by the heat generator with refrigerant such as water circulating through the passage, thereby cooling the heat generator.
Generally, a cooler is connected to a radiator and a pump through a tube or a hose for circulating refrigerant. Since refrigerant used for the cooling device is contaminated by foreign particles produced from component parts of the refrigerant circuit and due to the deterioration of walls of such component parts, there is a fear that the passage in the cooler is clogged with the foreign particles. To solve this problem, the cooling device disclosed in Japanese Application Publication 2007-205694 uses a filter for refrigerant to prevent a passage in the cooler from being clogged with foreign particles.
The cooling device disclosed in the above Publication is formed into an integral laminated structure in which an inlet side tube connection plate, a passage-enlarging plate, a filter plate, another passage-enlarging plate, an inlet side passage-restricting plate, a plurality of passage plates and heat transmission plates that are arranged alternately, an outlet side passage-restricting plate, another outlet side passage-enlarging plate and an outlet side tube connection plate are disposed in laminated arrangement in this order. Each heat transfer plate has formed at the center thereof a finned area and a micro passage is formed between any two adjacent finned areas of the heat transfer plates. Foreign particles contained in fluid flowing in from the inlet side tube connection plate are captured by the filter plate. Therefore, the cooling device according to the above Publication can prevent the micro passage formed between any two adjacent finned areas from being clogged with the foreign particles, thus preventing an increase of load of the pump and deterioration of the cooling performance and achieving effective cooling of the heat generator.
Foreign particles that are captured are attached to and deposited on the surface of the filter plate gradually in accordance with the operation of the cooling device and prevents smooth flow of refrigerant flow, so that the filter plate needs be cleaned periodically. In the cooling device according to the above Publication which is formed in a integral laminated structure of many components including the filter plate, however, it is difficult to remove the filter plate from the laminated structure for cleaning.
The laminated structure is formed by bonding the components together by any suitable means. Furthermore, heat generators are joined to a plurality of heat transmission plates in the laminate structure by brazing or soldering, so that it is practically impossible to disassemble the components in the laminated structure. Therefore, the filter sheet in the cooling device according to the above Publication cannot be cleaned, so that it is not suitable for use for a long time.
The present invention is directed to providing a cooling device which facilitates the removal of foreign particles attached to a filter.